Yes!Finale should have an option to treat accidentals in multiple layers as if all the accidentals were in the same layer. Don't forget to e-mail your feature request to
WINSUPPORT@makemusic.com
or
MACSUPPORT@makemusic.com
and remember to include your Finale serial number.
There is a workaround: Hide the accidentals, and add all the notes as chords in Layer 3. In Layer 3, hide noteheads and stems, and leave only the accidentals visible. It's a lot of work, but the result looks professional.
I am not sure how the feature request for articulations should be. Right now I have duplicate articulations, e. g. one fermata for single layer notation (on "Note Side") and one fermata for multiple layer notation (on "Stem Side"). But it is hard to keep track of all those articulations.
Peter Thomsen